The field of the disclosure relates generally to passive wireless sensors and, more particularly, to passive wireless sensors for turbomachines.
At least some known turbomachines, i.e., gas turbine engines compress air via a plurality of rotatable compressor blades and ignite a fuel-air mixture in a combustor to generate combustion gases that are channeled through rotatable turbine buckets via a hot gas path. Also, at least some other known turbomachines, i.e., steam turbine engines channel steam through rotatable buckets via a steam path. Such known turbomachines convert thermal energy of the combustion gas stream and steam, respectively, to mechanical energy used to rotate a turbine shaft. Output of the turbomachines may be used to power a machine, for example, an electric generator, a compressor, or a pump.
Many of these known turbomachines include known sensing devices that are configured to withstand high temperatures and the stresses and strains associated with high-temperature environments for only a short period of time, i.e., 100 hours or less. Some such known sensing devices include measurement instruments coupled to, within a gas turbine, for example, combustor assemblies. Such known coupled sensing devices typically require extensive wiring as well as modifications to the combustor assemblies to accommodate the wiring. Therefore, such measurement systems increase construction and maintenance costs.
Other known wireless sensing devices are deposited on the combustors through a printing process. Yet other known wireless sensing devices are formed in layers on the surfaces of the high-temperature components. Moreover, other known wireless sensing devices are embedded within the high-temperature components, e.g., inserted into slots defined within the components during manufacturing. Furthermore, some known wireless sensing devices require the substrate (for ground layers or ground plane) and dielectric features of the components to which the sensing devices will be affixed. These five methods of coupling, i.e., affixing sensors to high-temperature components require addition of at least some of the sensor components to the high-temperature components subsequent to manufacture of such components. As such, these methods lend themselves to adoption by non-original equipment manufacturers (OEMs). Moreover, post-manufacture affixing of portions of the sensing devices to the high-temperature components has a potential for not fully integrating the sensors with the high-temperature components. In addition, the most appropriate or desired position on the high-temperature components for affixing devices may not be available. Specifically, while certain portions of components or certain components exposed to high-temperature conditions, e.g., 500° Celsius (° C.) to 1000° C., and the associated substrates are coated appropriately, other components or portions thereof will be exposed to lower temperatures, e.g., approximately 200° C. will likely not be coated, therefore these regions will not have the necessary dielectric properties. Also, some component surfaces, i.e., substrates may be unacceptable as a substrate for the sensing devices.
Further, such issues with known stationary surfaces within a turbomachine are similar for rotational components therein, e.g., compressor blades and turbine buckets. Such rotational components also have additional issues such as high-velocity rotational effects and connectivity issues associated with the rotational operation of the monitored components and the difficulties with transmitting measurement data from the blades and buckets to an external data storage and analysis unit.